The invention relates to a deep-sea device and a method for recovering (retrieving) at least one preferably biological deep-sea object from the deep-sea, wherein the at least one deep-sea object comprises in particular at least one (vital or inanimate) biological organism and/or cell material of the same.
The deep-sea, even if the expression is not defined in common usage exactly with a depth range, represents the largest biotope of the Earth. In the following, deep-sea should be understood as the area of the oceans, seas or lakes, in which it is almost completely dark and organisms live, which are adapted to the conditions prevailing there (pressure, temperature, nutrient concentration, etc.) to the largest extent possible and must obligately live there the most time of their life span. This area begins approximately at a water depth of 1,000 m and ends, as currently known, at approximately 11,034 m (Mariana Trench, which is considered the deepest point of the Earth's oceans).
The average depth of the seas and oceans of the Earth is greater than 3,000 m and covers a surface of far more than half the globe. Notwithstanding the large areas, the knowledge on this portion of the biosphere is above all limited to the upper areas (down to a depth of approximately 3,000 m) and delimits locally very narrow ranges. This is mainly due to rather selective examinations based above all on technical and logistic problems, as well as to the considerable outlay, which is necessary with increasing depth in order to take deep-sea objects or samples, find, observe animals, or carry out other actions.
The deep-sea organisms are in many respects interesting from the scientific but also economical point of view. With increasing depth, they are obligately “barophilic” resp. “piezophilic”, i.e. adapted to the high pressure conditions of the deep-sea. They will not survive a significant pressure change. Technically, a live recovery of macro-organisms (not bacteria) is not even satisfactorily possible at this point in time up to a depth of 2,500 m [B. Shillito, G. Hamel, C. Duchi D. Cottin, J. Sarrazin, P.-M. Sarradin, J. Ravaux, F. Gaill, Live capture of megafauna from 2300 m depth, using a newly designed pressurized recovery device, Deep-Sea Research I 55 (2008) 881-889]. The reasons for the unsuccessful attempts for recovering living organisms or also only living cell material and the long-term stable establishment of propagatable in vitro cell cultures are in particular:                the increasing adaptation of the organisms to high pressures with rising depth and their constancy in the natural habitat,        the adaptation to either very constant low temperatures (approximately 1° C.-6° C.+/−0.1° C., psychrophilia) or high temperatures near hot sources (thermophilia) and the resulting low tolerance of the organisms with respect to temperature changes,        the optimization of almost all macromolecules to high pressures (up to approximately 110 MPa at a depth of approx. 11,000 m) and thus their functional and vitality reduction up to loss at low pressures,        the obligate piezophilia, which probably occurs from a depth of approximately 5,000 m as well as technical problems with activities like animal husbandry, cell culture, isolation methods, etc. under such high pressures, which have not been solved satisfactorily and in a handy manner up to now,        the availability of suitable catching and transfer devices from a great sea depth,        the lack of experience as regards the management of organisms and the lack of knowledge of their physiological properties, nutrition, etc.,        the considerable time pressure while transporting the animals from the depth to isolation of the cells since, hitherto, no corresponding exactly working transfer systems exist.        
In particular, the following two reasons have for decades made the recovery of deep-sea objects, preferably of at least living tissue material of deep-sea macroorganisms, necessary.
First, a necessity for scientific studies. Deep-sea organisms of whatever species can only be transferred alive to a laboratory husbandry or at least via the cultivation of cells to the regular laboratory cultivation operation, since any provision of sufficient material for research then also exists. The deep-sea can only be visited in the short term. No permanent laboratory unit exists at this point in time and would be comparable, as far as the technical complexity is concerned, with a space station. On the other hand, the desire for economical exploitation of larger stocks or to have a correspondingly large amount of biomaterial available for commercial use. Only in biolaboratories on the Earth's surface can cells, macromolecules and other substances of the deep-sea organisms be isolated in sufficient quantities, and animals, or also cells, if applicable, be cultivated and expanded to the required quantities, modified and thus economically used, since the organism density of the deep-sea is mostly extraordinarily low and thus doesn't allow for commercial captures.
For biotechnology, living cells, small tissue complexes and macromolecules are above all interesting, whereas for science the vital animals are rather of primary interest. Also the stabilization of isolated, living cells and their culture was up to now successful only up to unsatisfactory depths. For deep-sea organisms of the megafauna, this is a depth of approximately 1,162 m [S. Koyama, Cell biology of deep-sea multicellular organisms, Crytotechnology (2007) 55:125-133]). Here, besides this, it was hitherto all about organisms, which tolerate a significant pressure drop to normal pressure to a great extent, i.e. are not obligately piezophilic (e.g. the deep-sea eel). The majority of the obligate deep-sea organisms are located at greater depth and therefore hitherto have not been represented and accessible with their macro-organism spectrum in laboratory cell cultures.
Hitherto, the following two approaches are substantially followed for recovering deep-sea objects.
First, the recovering of the deep-sea objects caught without maintaining the depth pressure at the place of catching. On the other hand, the recovering in pressure chambers on deep-sea vessels and transferring to the surface with more or less good maintenance of the pressure in the original area of life of the deep-sea object caught. In the first option, only organisms, which are not macro-organisms (e.g. bacteria) and are not obligately piezophilic can survive. The methods are therefore limited to depths that are smaller than approximately 2,000 m. The second option implies ascent times in the hour range and requires therefore very exact thermostating and pressure stabilizations. Also, significant depth limits are set here, and no vital recoveries were successful, except the said ones.
It can be assumed that from the sum of said reasons for a live recovery of macro-organisms of the deep-sea resp. the installation of cell cultures from intact cells of an obligately piezophilic organism (e.g. fish, crustacean, etc.) novel devices and methods are required, i.e. the currently known technology with the approach of catching chambers which can be adjusted more or less well in terms of pressure and temperature is not sufficient.
An essential reason for the loss of vitality of the whole organism as well as the life processes at the cellular level consists in the currently required long ascent times from a great depth in mostly sub-optimal marginal conditions (in particular pressure, temperature, light). This way, the ascent operation has, for a depth of 7,000 m and an already favourable ascent speed of a conventional underwater vessel or conventional catching system of 1 m/s a duration of 7,000 s, i.e. almost 2 hours. With the time period necessary for the recovery, the time required until removal of the organism is mostly equal to several hours.
With respect to the general prior art, reference is also made to WO 2010/145791 A2, which, however, only describes a very slow, passive buoyancy of a catching device e.g. by means of a balloon and is thus not suitable for the purpose of the invention. Reference is also made to EP 1 493 656 A1, which describes a conventional submarine, which is, however, not suitable for the deep-sea and thus not suitable for the purpose of the invention.
An object of the invention is to create an improved deep-sea device and an improved method for the recovery of at least one deep-sea object.
In particular, it is an object of the invention to create a deep-sea device and an associated method, which allow the vital recovery of at least one deep-sea object (preferably a macro-organism) at least at the cellular level and optionally to transfer cells into a stable propagatable in vitro culture.
These objects are achieved in particular with a device and a method having the features of the invention.